Slide fastener



March 13, 1945. v @ZEK 2,371,591

sLIpE FASTENER Filed Oct. 23, 1943 Patented Mar. 13, 1945 sLmn ms'rnnan Vojtech Cizek, Astoria, N. Y., assignor to Waldes Koh-I-Noor, Inc., Long Island City, N. Y., a corporation of New York Application October 23, 1943, Serial No. 50i,444

' element according to the invention attached to its 12 Claims.

This invention relates to improvements in slide fasteners and is directed more particularly to slide fasteners ofv the type employing scoops or interlocking elements made of non-metallic materials such as plastic material.

In slide fasteners of this type, it is known to form the scoops or elements symmetrically so that the slider can operate in either direction on the chain, the symmetrical formation of the elements permitting the fastener to be opened with either upward or downward movement of the slider. Such symmetrical elements are usually provided with protruding teeth-like heads connected to the jaws thereof by neck-portions so that the head parts of the elements can enter the recesses formed in or by the neck parts of opposite inter-engaging elements. To prevent longitudinal and lateral separation of the elements after-they have been engaged, additional means are usually provided on the head and neck parts of the elements, such as interfitting pins on the heads and holes in the neck portions for the pins. Obviously, the resulting elements are of relatively complicated form which makes their manufacture by the conventional molding or casting processes difficult and delicate, the element construction moreover resulting in a non-flexible fastener unless provided with special means permitting relative movement of the engaged elements required to impart the necessary flexibility to the fastener.

Accordingly, the main object of this invention is to overcome the difficulties of prior fasteners of thetype under consideration by providing a special form of fastener element therefor which assures a perfect locking action in both longitudinal and crosswise direction as well as substantial flexibility of the fastener about its longitudinal as well as its transverse axis; and which furthermore facilitates the manufacture of the elements by stamping, casting or molding from plastic material.

Other objects will be in part obvious and in part hereinafter pointed out in connection 'with the followinganalysis of this invention wherein is illustrated an embodiment of the-invention in detail.

In the drawing-- 7 Fig. 1 is a fragmentary enlarged view of a slide fastener chain according to the invention in closed position; 7

Fig. 2 is a front view of a slide fastener employing a fastener chain, as illustrated in Fig. 1 with its slider attached thereto;

tape; and

Fig. 4 is a plan view of the fastener element illustrated in Fig. 3.

In the drawing, wherein like reference characters designate like parts throughout the several views, reference characters l0, ll designate the tapes or stringers of a slide fastener chain having edge beads l2, l3, respectively, to which are secured rows ll, ii of oppositely disposed scoops or fastener elements of the special construction to be described. The fastener elements are adapted to be engaged and disengaged by a slider I 6 operating in more or less conventional manner to close and open the fastener.

As seen in.Fig. 4, the elements are formed symmetrical about a longitudinal center line which extends transverse to the longitudinal axis of the fastener, so that the elements present.

body provided at its rear ends with jaws l1, l1,

which are adapted to be clamped over'the tape beads in usual manner, and with a head or working end l8 connected to the securing end by an intermediate neck part i9. As seen in Figs. 3 and 4, the head end of the elements is formed as a protruding ball or sphere segment whose diameter is slightly less than the depth of the fastener body when the latter is viewed in side elevation, being disposedbetween the pointed ends 20, 20' of the body so that the spherical head is in effect joined at its poles to the pointed ends, the body sides defining the latter extending vertically to Fig. 3 is an enlarged side edge view of a fastener intersect the outer spherical surface of the head. Due to this positioning of the protruding ballor sphere segment relative tothe pointed ends of the element body, a substantial circumference of the ball or sphere segment lies beyond and to each side of the fastener body as seen in plan view in Fig. 4. I

The neck portion l9 has formed on eachside thereof a part spherical cavity or seat 2|, so that the seats open to the sides of the fastener body as seenin Fig. 3. Preferably, the-radius of ourvature of the segmentalheads l8 and of the seats 2| is substantially the same, but the depth of the seats is somewhat less than their radius of curvature, with the result that the seats are relatively shallow. r

The element body is preferably formed with flat upper and lower faces 22, 23 to insure plane riding surfaces for the slider l6. Moreover, due to the depth of the fastener body being greater than the diameter of the head segments and the pointing of the working end of the body, sharp edges in the vicinity of the outer head circumference are avoided, and smooth operation is-accordingly assured. -As will be observed from Fig. 4, the pointed ends 20, 20 of the bodydiverge outwardly along gradual edge curves 24, 25 to merge into the securing end of the element which latter thus may have appreciable width W. With the curved side edges of the body in effect overhanging the ball seats, thereby insuring good locking action, the curvature of'the side edges also permits an element to flex in its own plane relative to adjacent elements without interference. The increased width of the fastener body at its securing end is moreover advantageous in increasing the gripping action of the jaws on the tape beads l2, l3.

With the specialformation aforesaid, engaged fastener elements provide a substantially perfect locking action due to the fact that the spherical head of each element is adapted to mate with the oppositely opening seats and the heads of two opposite. elements, in the manner illustrated in Fig. 1. Longitudinal and crosswise separation of the so mated elements is accordingly prevented.

Despite the positive locking action aforesaid, the

mating head and the seat surfaces provide in effect a series of universal joints along the length of the fastener and accordingly the latter is free to flex in any direction as required by the forces effective thereon, the curved side edges of the a fastener elements offering no interference to such flexing action. The formation of the elements is moreover such that the elements lend themselves to manufacture by the usual stamping, casting or molding processes.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above descripthat the head of each element is adapted to mate with the adjacent seats and the heads of two opposite elements.

2. A slide fastener as set forth in claim 1, wherein the depth of the part spherical seats is less than the radius of thehead.

3. A slide fastener as set forth in claim 1, wherein the element heads and seats have the same radius and curvature.

4. A slide fastener as set forth in claim 1, wherein the element heads and seats have substantially the same radius of curvature, and the depth of the seats is less than said radius.

5. A slide fastener comprising a chain of oppositely disposed fastener elements arranged in rows and a slider for engaging and disengaging the same, the elements each comprising a body provided at one end with securing means and converging to a point at its other end, said pointed end being formed with. a part spherical head of diameter less than the depth of the body and whose circumference extends beyond and to the sides of the body proper, the body intermediate its ends and on each side thereof being provided with' part spherical seats so that the head of each element is adapted to mate with the adjacent seats and the heads of two opposite elements.

6. A slide fastener as set forth in claim 5, wherein the depth of the part spherical seats is less than the radius of the head.

7. A slide fastener as set forth in claim 5,

wherein the element heads and seats have sub- I stantially the same radius of curvature.

8. A slide fastener as set forth in claim 5,

wherein the element heads and seats have the same radius of curvature, and the depth of the seats is less than said radius.

9. A fastener element for a slide fastener comprising a body having securing jaws formed at one endand side edges which converge to a point at its other end, the pointed end being formed with a part spherical protruding head of diameter less than the depth of the body, the body intermediate its ends and on each side thereof being provided with part spherical seats adapted to receive the heads of adjacent oppositely arranged elements.

10. A fastener element as set forth in claim wherein the head and seats have substantially the same radius of curvature.

. 12. A fastener element as set forth in claim 9,

wherein the body has plane top and bottom faces, and in which the body sides extend along a curvature such that the securing end of the body has substantial width.

VOJTECH CIZEK. 

